I have extended the Project Explorer with the Common Navigator Framework so it displays my own resources within my own ProjectNature. These resources do not have a file system representation. They therefore do not implement IResource.

I would like to use these resources with properties now.

I haven't found a description how properties are saved. I assume that this is happening automatic. I suppose this will only work if the resources implement IResource (where else should Eclipse find a file system path and file name for the properties).

How can I make my resources implement (or adapt to) IResource? The JavaDoc says that a clients shall not implement IResource.

I would like to use the existing properties mechanism so other Plug-Ins can add properties to my resources.

Thanks for the quick answer.
I have seen this article before and have already scanned through it. I think it doesn't explain how the properties are saved to the *.properties file, or is this to automatism but have to be individually programmed?

When I right click something (like a Java Project or Package) in the Project Explorer and select Properties, a Window opens where I can edit properties (for instance for a Java Package it says that it is an IFolder element that has Properties for the categories Run/Debug Settings, Resource, Subversion.

I think that several plugins (like the Subversion Plug-In) can add property categories and that these are stored somewhere in a persistent property file that is connected to the package. Therefore they are reloaded the next time I open Eclipse.

Ok, this is how to get the property page installed in the UI framework. The initial question was how the properties entered there are saved as persistent properties to reappear in the next session. I see no other way to provide a filename for the resource than to implement the IResource interface. However the JavaDoc says that clients shall not implement it.

An off topic question: Is it normal, that I am not allowed to write more often than every 5 hours on this forum? If I do it tells me that I am spamming the forum, so I may not even be able to reply to messages in my topic.

It should allow you to post immediately as far as I know. You could send an email to the webmaster or file a bug against the Eclipse Foundation on this point.

Regarding keeping properties persistent. If you only have a small amount of properties, then you can use the persistent properties mechanism associated with the resource (see IResource.setPersistentProperties). It's really only designed for a small amount of information though (under 2K).

And another issue is that it's only stored with the resource while it's in the workspace. That is if you check in this file you need to make sure you store the properties in another form as this will not follow the file into source control. You also have to design your property sheet to update these.

I do use these for some things in my RCP application and I keep a parallel file in .settings at the project level that records the persistent properties for all of the resources in the project. That way this file can be checked in and out with the project so that the project can be moved across workspaces. This is work you have to so yourself though.